BD_Integratoren/src/Integratoren2d_force.cpp
2021-10-25 18:45:54 +02:00

195 lines
7.3 KiB
C++

//
// Created by jholder on 21.10.21.
//
#include "Integratoren2d_force.h"
#include "vec_trafos.h"
using Vector = Eigen::Vector2d;
using Matrix = Eigen::Matrix2d;
void Integratoren2d_force::Set0_deterministic(Rod2d &rod2D,
Simulation & /*sim*/) {
auto trans_lab = Vector({0, 0.01});
rod2D.setPos(rod2D.getPos() + trans_lab);
Eigen::Rotation2D<double> rot(0.1);
rod2D.setE(rot * rod2D.getE());
}
const Vector Integratoren2d_force::unitVec = {1, 0};
void Integratoren2d_force::Set1_Euler(
Rod2d &rod2D, Simulation &sim,
const std::function<Vector(Vector, Vector)> &force,
const std::function<double(Vector, Vector)> &torque) {
auto std = sim.getSTD(); // sqrt(2*delta_T)
// translation
Vector rand = {sim.getNorm(std), sim.getNorm(std)}; // gaussian noise
Vector trans_part = rod2D.getDiff_Sqrt() * rand;
Vector trans_lab = rotation_Matrix(rod2D.getE()) * trans_part;
// Force
Vector F_lab = force(rod2D.getPos(), rod2D.getE());
Vector F_part = rotation_Matrix(rod2D.getE()).inverse() * F_lab;
Vector F_trans = rod2D.getDiff_Sqrt() * F_part;
F_trans *= sim.getMDeltaT();
// rotation
double rot =
sim.getNorm(std) * rod2D.getDRot_Sqrt(); // rotationsmatrix verwenden.
Vector e = rod2D.getE();
double M_rot = torque(rod2D.getPos(), rod2D.getE()) * rod2D.getDRot() * sim.getMDeltaT();
Vector new_e = e + (rot + M_rot) * ortho(e);
new_e.normalize();
// apply
rod2D.setPos(rod2D.getPos() + trans_lab + F_trans);
rod2D.setE(new_e);
}
Vector Integratoren2d_force::Heun_predictor_pos(
const Rod2d &rod2D, Simulation &sim,
const std::function<Vector(Vector, Vector)> &force) {
auto standard_dev = sim.getSTD();
Vector rand_pred = {sim.getNorm(standard_dev),
sim.getNorm(standard_dev)}; // gaussian noise
Vector trans_pred_part =
rod2D.getDiff_Sqrt() *
rand_pred; // translation vector in Particle System
Vector trans_pred_lab = rotation_Matrix(rod2D.getE()) * trans_pred_part;
Vector F_pred_lab = force(rod2D.getPos(), rod2D.getE());
Vector F_pred_part = rotation_Matrix(rod2D.getE()).inverse() * F_pred_lab;
Vector F_pred_trans = rod2D.getDiff_Sqrt() * F_pred_part;
F_pred_trans *= sim.getMDeltaT() ;
return F_pred_trans + trans_pred_lab;
}
Vector Integratoren2d_force::Heun_predictor_rot(
const Rod2d &rod2D, Simulation &sim,
const std::function<double(Vector, Vector)> &torque) {
auto std = sim.getSTD();
double rot_predict =
sim.getNorm(std) * rod2D.getDRot_Sqrt(); // rotationsmatrix verwenden.
const Vector& e = rod2D.getE();
double M_predict_rot = torque(rod2D.getPos(), rod2D.getE()) *
rod2D.getDRot() * sim.getMDeltaT();
Vector e_change_predict = (rot_predict + M_predict_rot) * ortho(e);
return e_change_predict;
}
void Integratoren2d_force::Set2_Heun(
Rod2d &rod2D, Simulation &sim,
const std::function<Vector(Vector, Vector)> &force,
const std::function<double(Vector, Vector)> &torque) {
Vector delta_pos_predictor = Heun_predictor_pos(rod2D, sim, force);
Vector pos_predictor = rod2D.getPos() + delta_pos_predictor;
Vector delta_e_predictor = Heun_predictor_rot(rod2D, sim, torque);
Vector e_predictor = rod2D.getE() + delta_e_predictor;
e_predictor.normalize();
Rod2d pred_rod = rod2D;
pred_rod.setPos(pos_predictor);
pred_rod.setE(e_predictor);
Vector delta_e_future = Heun_predictor_rot(pred_rod, sim, torque);
Vector e_integrated =
rod2D.getE() + 0.5 * (delta_e_predictor + delta_e_future);
// apply
rod2D.setPos(pos_predictor);
rod2D.setE(e_integrated.normalized());
}
void Integratoren2d_force::Set3_Exact(
Rod2d &rod2D, Simulation &sim,
const std::function<Eigen::Vector2d(Eigen::Vector2d, Eigen::Vector2d)>& force,
const std::function<double(Eigen::Vector2d, Eigen::Vector2d)>& torque) {
auto std = sim.getSTD(); // sqrt(2*delta_T)
// translation
Vector rand = {sim.getNorm(std), sim.getNorm(std)}; // gaussian noise
Vector trans_part =
rod2D.getDiff_Sqrt() * rand; // translation vector in Particle System
Vector F_lab = force(rod2D.getPos(), rod2D.getE());
Vector F_part = rotation_Matrix(rod2D.getE()).inverse() * F_lab;
Vector F_trans = rod2D.getDiff_Sqrt() * F_part;
F_trans *= sim.getMDeltaT();
Vector trans_lab = rotation_Matrix(rod2D.getE()) * trans_part;
// rotation
double rot =
sim.getNorm(std) * rod2D.getDRot_Sqrt(); // rotationsmatrix verwenden.
Vector e = rod2D.getE();
double M_rot = torque(rod2D.getPos(), rod2D.getE()) * rod2D.getDRot() * sim.getMDeltaT();
auto correction =
-0.5 * pow(rod2D.getDRot(), 2) * sim.getMDeltaT();
Vector new_e = e + (rot + M_rot) * ortho(e) + correction * e;
new_e.normalize();
// apply
rod2D.setPos(rod2D.getPos() + trans_lab + F_trans);
rod2D.setE(new_e);
}
void Integratoren2d_force::Set4_BDAS(
Rod2d &rod2D, Simulation &sim,
const std::function<Eigen::Vector2d(Eigen::Vector2d, Eigen::Vector2d)>& force,
const std::function<double(Eigen::Vector2d, Eigen::Vector2d)>& torque) {
auto std = sim.getSTD(); // sqrt(2*delta_T)
Vector e = rod2D.getE();
// translation
Vector rand = {sim.getNorm(std), sim.getNorm(std)}; // gaussian noise
Vector trans_part = rod2D.getDiff_Sqrt() * rand;
Vector trans_lab = rotation_Matrix(rod2D.getE()) * trans_part;
// Force
Vector F_lab = force(rod2D.getPos(), rod2D.getE());
Vector F_part = rotation_Matrix(rod2D.getE()).inverse() * F_lab;
Vector F_trans = rod2D.getDiff_Sqrt() * F_part;
F_trans *= sim.getMDeltaT();
// rotation
double rot =
sim.getNorm(std) * rod2D.getDRot_Sqrt(); // rotationsmatrix verwenden.
double M_rot = torque(rod2D.getPos(), rod2D.getE()) * rod2D.getDRot() * sim.getMDeltaT();
Vector new_e = Eigen::Rotation2D<double>(rot + M_rot) * e;
new_e.normalize();
// apply
rod2D.setPos(rod2D.getPos() + trans_lab + F_trans);
rod2D.setE(new_e);
}
void Integratoren2d_force::Set5_MBD(Rod2d &rod2D, Simulation &sim,
const std::function<Eigen::Vector2d(Eigen::Vector2d, Eigen::Vector2d)>& force,
const std::function<double(Eigen::Vector2d, Eigen::Vector2d)>& torque) {
Vector delta_pos_predictor = Heun_predictor_pos(rod2D, sim, force);
[[maybe_unused]] Vector pos_predictor = rod2D.getPos() + delta_pos_predictor;
Vector delta_e_predictor = Heun_predictor_rot(rod2D, sim, torque);
Vector e_predictor = rod2D.getE() + delta_e_predictor;
e_predictor.normalize();
auto std = sim.getSTD();
Eigen::Vector2d e = rod2D.getE();
Eigen::Matrix2d Diff_combined = 0.5*(rod2D.getDiff() + rotation_Matrix(e).inverse() * rotation_Matrix(e_predictor)*rod2D.getDiff());
Eigen::Matrix2d D_combined_sqrt = Diff_combined.llt().matrixL();
auto rand = Eigen::Vector2d(sim.getNorm(std), sim.getNorm(std));
Eigen::Vector2d pos_integrated =rod2D.getPos() + rotation_Matrix(e) * D_combined_sqrt * rand;
double rot = sim.getNorm(std) * rod2D.getDRot_Sqrt();
Eigen::Vector2d e_integrated = e + 0.5 * (rot * ortho(e) + rot * ortho(e_predictor));
//apply
rod2D.setPos(pos_integrated);
rod2D.setE(e_integrated.normalized());
}